Deep water grow beds??

[Roger R.]

I've been planning the solar greenhouse that I would like to build and want to incorporate some water barrels along the back wall for some thermal mass. But I also would hate to lose the space for growing plants, so I came up with this idea.
A row of 55 gallon barrels with the top 10 or 12" used for a grow bed and a couple of feet of water under. The growing media would be supported by some kind of screen on pvc legs and they would flood and drain in the top section only. I could set them up in groups of four all plumbed together at the bottom and just below the screen.
They would drain to their own sump and the more standard grow beds across the front of the green house would go to another sump.
Two pumps to a constant height fish tank, then through a single set of filters and then diverted to the two systems.

Maybe this has been done before and failed, I don't know. I've got all winter to plan so any input is welcome.

I suck at Google Sketchup so here is a scanned drawing to show what I'm talking about. I'm working on the layout of the whole system and the greenhouse design, I'll post more of that when I get it like I want.

[alex281]

Welcome to the forum!

If at all possible, maybe try finding a way to mount the barrels sideways? this would give you more usable grow area, however if space is a tight option then what you have now is sure better than nothing!

[davidstcldfl]

Working on my morning coffee, so here are some random thoughts Roger...

You would be adding more water to the system, which helps for a more stable system.

I think gunk/solids will eventually build up in the bottom of the barrels, ceating an anarobic mess.

The heat your wanting to 'store' in the barrells, would be going into the entire system. Good in winter, bad in summer (depending where you live and the fish you raise)
Paint them black for winter, and wrap them with some reflective foil in the summer, if needed.

Why not add the barrels, and use them as 'stands' to hold some beds on top. Maybe 1/2 barrels like Alex mentioned, or mixing tubs ?
These barrels are used for making 'tea', but it may give you some ideas...

[keith_r]

the media provides surface area for the bacteria you need in an ap system to convert ammonia to nitrites then nitrates..
fill it with media to provide more surface area, which will also improve your stocking density (more surface area=bigger bioload)

[Roger R.]

Thanks for the replies. Yeah I was overthinking this, it would be best just to use the thermal mass barrels as stands for more growbeds. The water in the barrels can be treated to prevent algea and no addtional plumbing.
The barrels I woud get are already black with removable lids.

My greenhouse design will have insulated walls on the North and part way down both ends. A pitched roof on the back half and the front will be small, curved laminated arches. These will be covered with reinforced plastic sheet and designed so I can roll it up for summer ventilation. I'll post some drawings soon.